Fluid distribution systems, for e.g. heating, cooling and water supply are designed to feed a fluid from a source to a consumption point. Each consumption point typically has a calculated and designed flow or differential pressure requirement. However, depending on the type of hydronic system, the flow requirement is often variable over time and can change with factors like seasonality (e.g. summer or winter), that changes the load from the consumption points, temperature changes of the system fluid, changes in consumption of the system fluid (e.g. for drinking water).
Control valves are frequently used in fluid distribution systems and have a variable opening such that the flow rates can be controlled.
Balancing and control valves provide an additional feature/function. To balance the system, a hand wheel of the valve is turned for presetting a maximum opening of the valve, i.e. a maximum flow through the valve. For instance, for a valve having a valve seat with which a movable valve disc is cooperateable, the mechanics coupled to the hand wheel will limit how far from the valve seat the valve disc is allowed to move. An actuator of the valve will notice that the valve cannot be opened more and a control part can therefore be calibrated to control the movement of the valve within the set limits.
While the presetting function provided by existing balancing and control valves is beneficial for obtaining desired flows in, for instance, different parts of a building, they have the drawback that they are relatively complex and costly compared to ordinary valves without the balancing function.